The Gln27Glu β2-adrenoceptor polymorphism slows the onset of desensitization of cardiac functional responses in vivo

Studies performed in vitro have shown that the Arg16Gly allele in β2-adrenoceptors (β2AR) enhances susceptibility to agonist-induced down-regulation, while the Gln27Glu polymorphism diminishes it. In this study, we tested whether similar phenotypes occur in vivo. We assessed 32 volunteers (mean age